Generally, synthetic resins have excellent characteristics and hence are used in various applications such as molded products and films. However, synthetic resin products are likely to be electrostatically charged due to the hydrophobicity of synthetic resins. Hence, such a synthetic resin has major drawbacks in that, for example, dirt or dust adheres to a product to deteriorate the appearance of the product, electrical failure is caused during processing, and a malfunction occurs when such a synthetic resin is used in electronic equipment.
Conventionally, as a means to solve these drawbacks, a method of adding various surfactants such as anionic surfactants, cationic surfactants, and nonionic surfactants has been practically employed. The method of adding such a surfactant is excellent in antistatic properties for a short period of time after the formation of a product, but the surfactant bleeds out on a product surface and is removed by, for example, friction and water washing and it is thus difficult to preserve the properties for a long period of time. In addition, the synthetic resin product is molded at a high temperature, which causes thermal decomposition of the surfactant partially, and this may cause smoking during molding and coloring of the product. In order to provide antistatic properties to a multi-layered film and sheet of a synthetic resin, an antistatic agent is required to be added not only to a surface layer but also to a core layer. This increases the amount added, resulting in economic disadvantage.
In recent years, as means for solving the drawbacks and problems caused by using such a surfactant, a formulation containing a polyetheresteramide as a main component and an acid-modified polyolefin or other components as a third component (Patent Document 1) and a polymer antistatic agent having a cationized maleimide structure (Patent Document 2) have been proposed, but they still have insufficient performance. Polymer antistatic agents that are copolymerized products of a modified polyolefin and a multifunctional hydrophilic group have also been proposed (Patent Documents 3 and 4), but there is a problem in that the polymer antistatic agents are effective in a molded product but do not provide stable performance in a film and a sheet. In particular, a film to be used as a member in a touch panel, a deflecting plate, and others is required to have high optical homogeneity, but lines and fisheyes are generated in these related-art films and the films have insufficient appearance and transparency.